The LATTE study is an extension study to the now closed Arimidex, Tamoxifen Alone or in combination (ATAC) trail that took place 10 years ago. LATTE aims to collect long term follow-up information since the conclusion of ATAC, and for at least another 5 years, regarding: Additional efficacy data (first local recurrence, first distant recurrence), Additional safety data (ischaemic cardiac and cerebrovascular event, fractures), and Cause specific mortality and new primary cancers.